On-going research by Agricultural Research Service-funded scientists at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University also suggests that healthy whole foods eating habits are also directly connected to healthy eyes. Eating fruits, vegetables and whole grains rich in antioxidants translates into a lower incidence of cataracts—a clouding of the eye's lens that impairs vision and is found in almost half of all Americans over age 75. Researchers examined food questionnaires completed over 13 to 15 years by 478 nondiabetic women aged 53 to 73 who were participants in the Nurses' Health Study and had recently been diagnosed with cataracts. Those women whose diets had included more vitamin C, E, riboflavin, folate, beta-carotene, lutein and zeazanthin were found to have less cloudiness than women with the lowest intakes of these antioxidant nutrients.(December 3, 2003)
Good news, these are the World's healthiest foods!
What is it about the World's Healthiest Foods that gives them their valuable health-promoting effects? Simply stated their value is a reflection of both what they do contain and what they do not contain. Let's explore both perspectives so that we can fully appreciate how and why these whole, organically-grown foods support well-being and vitality.
All the Good Stuff
It is a consensus in the scientific field that a higher consumption of these healthy foods is associated with a reduced risk of myriad diseases and early aging. Scientists are now working on understanding exactly why whole foods provide health protection, and they have identified many compounds present in these foods that appear to be critical for prevention of chronic diseases. Among the most researched are the antioxidants, phyoestrogens, dietary fibers and resistant starches concentrated in foods such as fruits, vegetables, whole grains, and legumes.
The health-promoting effects of whole foods are thought to be partially related to their abundant and complex antioxidant profile. Fruits, vegetables, whole grains and other whole foods feature a spectrum of antioxidants, including vitamins C and E, the trace minerals selenium and zinc, and a palette of important phytonutrients such as flavonoids and carotenoids.
The protection that antioxidants confer is related to their ability to quench reactive oxygen species (ROS), such as free radicals and other unstable oxygen molecules that are present in our cells and can damage cellular membranes and alter genetic materials if not neutralized. These reactive free radicals and other damaging molecules come from UV radiation, toxins and pollutants that get into our bodies, and even from our own energy producing processes within our cells.
Free radicals and unstable oxygen species are known to promote the development of atherosclerosis, cancer, arthritis, diabetes and a host of other conditions.
It is also known that antioxidants can protect us from the damage these molecules produce in our cells, that different antioxidants provide protection to different parts of our bodies and cells, and that antioxidants work together as a team. Therefore, we need more than just a high amount of a single antioxidant, like vitamin C; we need the gamut of antioxidants provided by a varied whole foods diet to keep the reactive oxygen species like free radicals "in check," thus minimizing the damage they can cause.
Phytoestrogens, a special class of phytonutrients that include isoflavones and lignans, are found in plant-based foods such as soybeans, flaxseeds and berries. In the past few years, phytoestrogens have received recognition as yet another unique health-promoting feature offered by whole foods. Most notably, a significant number of research studies has shown that Asian populations who consume high levels of soy foods (tofu, soybeans, soymilk) that contain isoflavones, have lower levels of breast, ovarian and endometrial cancers.
These studies associating isoflavones with protection against estrogen-dependent cancers have caught the eye of university researchers all over the world, and even scientists within the federal government at such agencies as the National Cancer Institute. Given that breast cancer is one of the most common cancers in women, and its development appears to be associated with diet, scientists have been very interested in how isoflavones might protect against breast cancers. Subsequent experimental research has clarified shown that isoflavones are converted in the body to hormone-like compounds that have the ability to modulate estrogen activity and dampen its potentially damaging effects in cells within the female reproductive organs.
Dietary Fiber and Resistant Starches
Dietary fiber and resistant starches, compounds featured in plant-based whole foods (notably whole grains) are thought to be yet another contributor to their unique health-promoting qualities. In the large intestines, dietary fiber binds to carcinogens, excess hormone such as estrogens, bile acids, and toxins like pesticides, promoting their excretion from the body. Dietary fiber also supports healthy digestion and, since it is the preferred food of the cells that make up the lining of the intestinal tract, is necessary for a healthy intestinal tract overall.
Resistant starches, a unique class of carbohydrates, pass through the small intestine undigested and then proceed to the large intestine where they undergo fermentation. The by-products of this fermentation process include compounds called short-chain fatty acids(SCFA). One of these SCFAs is butyric acid, which is a compound that supports the health and healing of cells in the small and large intestine. Many research studies have demonstrated that butyric acid impedes the ability of cancer cells to proliferate in the colon, and therefore is protective of colon cancer. SCFAs have also been associated with helping to maintain healthy blood lipid and sugar levels.
Whole foods contain thousands of phytonutrients that have health-promoting properties, as well as vitamins, minerals, and macronutrients like fiber and beneficial fats. During processing, many of these compounds are removed. In particular, the essential omega-3 fatty acids, along with other unsaturated fats, are the first to be removed, in part, because they are often located in highest amounts in the outer surfaces of whole foods, and in part, because they are less shelf-stable in a processed food. They maintain their stability much better in the whole food where they are in their natural place. As an example, think about a fresh piece of tuna. When you cook fresh tuna along with it's skin, you get the tuna meat with all the omega-3 fatty acids that are so necessary to support your cells' membranes and promote health.
Now, compare that to canned tuna fish packed in vegetable oil. Not only are about 50% of the omega-3 fats missing, the taste itself has been compromised. StarKist (owned by SJ Heinz), currently claims 1.46 grams of total omega-3s per 6.5 ounce can of albacore tuna, (and this number doesn't change much in the water-packed versus oil-packed version.) This number is about half of the level that most sources report for fresh baked albacore. For the best flavor and nutrition, the superior choice is fresh tuna, cooked to perfection using one of wonderful Recipes developed for The World's Healthiest Foods. Next best choice is water-packed albacore, followed by oil-packed tuna.
When you eat whole grains, you get a high level of minerals, a range of vitamins including all of the energy-supporting B-vitamins, and the essential fats. When processed, a whole grain loses its bran, which contains most of its fiber, minerals, and B-vitamins; and its germ, which contains its essential fats and the family of protective vitamin E compounds called the tocopherols. From refined grains, you get a large amount of simple carbohydrates and starch, a bit of protein, and only a few vitamins from a food that started out with thousands of healthy compounds and a full spectrum of vitamins.
None of the Bad Stuff
The synergy of beneficial compounds inherent in whole foods may only be one piece of the puzzle as to why these foods are better for your health than un-whole foods. The other important aspect, complementing what whole foods do contain, is what whole foods do not contain.
Whole foods, by their nature, differ from refined foods in that they are not processed with an array of chemical additives. Some of these additives, although featured on the U.S. government's GRAS (generally recognized as safe) list and legally allowed to be added to the foods sold in this country, are thought to compromise the body's structure and function and are suggested to be related to a host of skin, pulmonary and psycho-behavorial conditions. (For more information on potentially harmful food additives, see Q&A "What Are the Problems with Conventional Foods?")
The Whole Story
The World's Healthiest Foods are whole foods whose benefits are, in part, derived from the fact that the nutrients they contain act in concert, rather than simply as single agents. These foods are therefore more than simply the sum of their individual parts. Although researchers have identified and typically focus on single compounds in whole foods that promote health (e.g., antioxidants, phytoestrogens, dietary fiber, and resistant starches), and compounds in refined, processed foods that are health detractors (e.g., synthetic chemical additives), this reductionistic focus only tells part of the story of why a diet rich in whole foods provides numerous health benefits.
The beauty of the World's Healthiest Foods, and their associated health benefits, seems to be a reflection of the natural synergy of all of their components: the totality of what they provide. This is not to say the benefits of each of the isolated components are not important - they are. It just means we should not lose the forest for the trees, that is, in their natural state in whole foods, these compounds work together synergistically.
Current scientific research supports this concept. Health-promoting foods work better when consumed containing as much of their original complement of nutrients as possible. Studies exploring the relationship between diet and health consistently show health benefits from eating minimally processed whole foods; whereas, studies focusing solely on isolated compounds have yielded mixed results.
An example of this is the research examining the relationship between beta-carotene and cancer. Epidemiological studies show a relationship between consuming whole foods high in beta-carotene, such as vegetables like carrots, with a lower risk of cancer. These observations have led researchers to test the effects of beta-carotene itself on preventing cancer. Studies using synthetic (chemically-made and purified) beta-carotene have not supported that beta-carotene, by itself, can protect against cancer. Instead, in some of these studies, people who smoke were found to have higher rates of cancer when given the synthetic beta-carotene supplement than smokers who did not take the supplement.
These apparently conflicting results -- foods high in beta-carotene showing cancer protection while synthetic beta-carotene supplements alone provided no protection -- have been baffling to scientists. In trying to understand the conflicting results, scientists have speculated that maybe, in fact, the protective effect of foods is due to more than just beta-carotene, maybe their protection requires the complimentary array of many or all the phytonutrients found in whole fruits and vegetables. Additionally, since the studies with the supplements used a specific synthesized form of beta-carotene, scientists have wondered if the range of carotenoids in whole foods, which include more than just this one beta-carotene form, would show the health-protective effects epidemiological studies show are provided by whole foods.
So, while a food's individual components may be important, research continues to support that our bodies need more than isolated nutrients; for optimal health, we need the full complement of phytonutrients in whole foods. This complement of thousands of health-promoting compounds provides a synergy of health-protecting effects in our bodies and is likely to contain many yet-to-be discovered beneficial components that are also integral to the vibrant health offered from the World's Healthiest Foods.